From the Research
The annual growth rate of the physis (growth plate) in the lower limb averages approximately 2-3 cm per year, though this varies significantly based on age and specific location. During peak growth periods, such as puberty, the distal femur can grow up to 1 cm per year, the proximal tibia about 0.6 cm per year, and the distal tibia around 0.5 cm per year 1. Growth is not constant throughout childhood; it's most rapid during infancy and adolescence, with a slower rate during middle childhood. Some key points to consider when evaluating growth patterns include:
- Boys typically experience their growth spurt between ages 12-16, while girls undergo this acceleration earlier, between ages 10-14 1.
- This differential growth timing explains why girls often temporarily overtake boys in height during early adolescence.
- Growth plates close (ossify) at the end of puberty, with lower limb physes generally closing between ages 14-16 in girls and 16-18 in boys.
- The growth process is regulated by complex hormonal interactions, primarily growth hormone, insulin-like growth factors, and sex hormones, which stimulate chondrocyte proliferation and matrix production in the physis. Understanding these growth patterns is crucial for properly timing interventions for limb length discrepancies and other orthopedic conditions affecting the lower extremities, as highlighted in studies on epiphysiodesis and limb lengthening 2, 3, 4.